I have this cassette on all four of my bikes. The spacing of the gears is excellent. The shifting is quick and reliable. The cogs seem pretty tolerant of cable adjustment variances. This cassette will work in any situation from flat to moderately steep terrain. For me, 9 cogs is all I need. 10-11-spd systems are overkill. I would only switch to a 10-spd system if Shimano offered a cassette with all the cogs of the CS-6500 plus a 34T. I would use that on my touring bike. For my other bikes, I'd stay with this cassette. This cassette upgraded the performance of my bikes substantially.

It was time to replace a worn 9 speed cassette. I also hoped to upgrade the part as well. The original cassette was a 12/25 Tiagra. The new 12/27 is much better. I can maintain tempo while climbing with the 27. Happy I made the change.

I upgraded from a 12-25 cassette on stock Alex 350 32 spoke wheels to Vuelta Corsa Lites with 11-23 cassette, what an impressive difference, accelerates nicely and looks sporty. My AL-1 is my first road bike/experiment changing out cranks first, the fork from stock aluminum to fiber carbon, and now the wheels and cassette, the wheels and cassette gave it a complete new feel. Bring on the San Diego Bike Tour!

This is a great cassette, with great shifting (Dura Ace 9-speed setup). But as I'm getting older and looking for value buys, I'm starting to wonder about technology that trickles down. In this case, a recently purchased HG-50 (Tiagra level) equivalent 12-27 gearing cassette for my cross bike shifts equally well, weighs only 10g more (232g vs. 242g), and costs less than half of the Ultegra. Your choice!